Mill-liner.



W. S. MCKEE.

Mm LINER.

AFPUCATION FILED FEB. 5 QI. E, 32899501 D Patent/@ Dec. 3L 9l8.

WALTER S. MCKEE, OF CHICAGO, ILLINOIS, ASSIGNOR T0 AMERICAN MANGANESE STEEL COMPANY, AUGUSTA. MAINE, A COBPOBATIQN 0F MAINE.

MILL-LINER.

Application led February To all whom t may concern:

Be it known that l, WALTER S. MGKEE, a citizen of the United States, and a resident of Chicago, in the county of Cook and State of Illinois, have made and invented certain new and useful Improvements in Mill-Liners, of which the following is a specification.

My invention relates to liners such as are used in tube and ball mills.

lt is an objectof my invention to provide -a mill liner which is so formed, con structed, and anchored in place, that each plate may stretch or ow [without bringing undue strains' upon the holding bolts, and without danger of stretching the mill shell or buckling the liner plates themselves.

A further object is to provide a mill liner wherein each lining plate is anchored and securely held in place by fastening means extending through the center thereof .and at which point is also located a removable lifting bar; and to provide means whereby the stresses and strains brought to bear upon the lifting bars are not transmitted to the fastening means, but are taken up and borne by ribs which extend along, and are formed integral with, the various lining plates.

lf have found that lining plates when provided with lifting bars are subject to unequal wear and that the greatest wear occurs midway between adjacent lifting bars. rThis greatest wear is also accompanied by a flowing and stretching of this portion of the lining plate. In order to overcome the disadvantages resulting from theunequal wear of the lining plate and the occurrence of the greatest wear at a particular point, and at the same time in order to realize and obtain the advantages and desirable features of a comminuter plate having lifting bars, I have provided my lining plates with a preponderance ofvmetal at those points at which the greatest wear occurs, thereby materially lengthening the life of the lining plate, decreasing the amount of metal .which is scrapped when taken with relation to the' initial weight of the lining plate, and at the same time preventing the lining plate from flowing or stretching. In accomplishing the aforementioned ends, I have provided eachlining plate with a lifting bar midway between its side edges and constructed the lining plate itself so that it gradually increases Specification of Letters Patent.

6, 1917. Serial No. 146,86.

Patented Dec 31, 1918.

in thickness from its center toward its side edges.

Other objects and advantages of my improved mill liner will appear as the description proceeds, wherein it is to be understood that changes in the precise embodiment of the invention can be made .within the scope of what is claimed without departing from the spirit thereof.

In accomplishing the above-mentioned objects, and in attaining the enumerated ends, I have provided a mill liner which is disclosed in its preferred embodiment in the accompanying drawings, wherein:

Figure 1 is a view in vertical section of a portion of a mill, equipped with my improved liner;

Fig. 2 is a view in perspective of one of the lining plates or slabs;

Fig. 3 is a ,rear view thereof; and

Fig. 4 is a detail view in perspective of a lifting bar.

Referring specifically to the several views, the liner is composed of a series of lining plates or slabs 10, through the center of which extend suitable openings 11 which correspond to, and are adapted to register with, similar openings 12 in the mill shell. Suitable fastening bolts 13 extend through the openings in the liner plate and the registering openings in the mill shell, and securely lock and anchor the central portion of the lining plates in place.

The fastening bolts 13 also hold in place the removable lifting bars 14, the same being. provided with the openings 15 through wh1ch the fastening bolts extend, and surroundmg'which openings are the bosses 16. the construction disclosed being such that the fastening bolts are held against rotation by the side walls of the openings 15 in the holding bars. do not wish to limit my invention to the exact construction of the holding bolts illustrated in the drawings, as these fastening means may be somewhat modified if desired.

lln order to relieve and prevent the hold- 1 ng bolts from being` subjected to the strains, jars and impacts .which are brought to bear upon the lifting bars, I provide each lining 'plate with a longitudinally extending supporting rib 17. These ribs are formed integral with the lining plates and are located adjacent the centrally disposed openings 11 supporting rib from lining plates side edges 20, and the width of the plates is such that a gap or space 21 is' defined between the side edges of adjoining plates, allowing the plates to stretch or iow. The severe action to which the lining plates are necessarily exposed in service, causes the plates to stretch and How, and although I have reduced this stretching and flowing to a minimum by increasing the thickness of the plates toward the side edges, the construction of my lining plates'is such that the stretching and flowing of the plates may take place without danger of shearingthe holding bolts, or causing the lining plates to buckle or become distorted. The central securement of the lining plates and the pro vision of openings between adjoining plates also prevent the mill shell fro-m being subjected to destructive tensional strains.

The increased thickness of the lining plates towardv their side edges, materially lengthens the serviceable life of each lining plate, as the greatest amount of wearing metal is located intermediate the lifting bars, which arrangement, it has also been found, increased the effective action of the liner as a Whole. The lining plates may be provided with small lugs 22 extending from the non-wearing surface thereof, which lugs rest against the inner surface of the Amill shell and support the lining plates or slabs thereabove.

What I claim is N 1. A lining plate for mills, the same being vthinnest at its central portion and increasing in thickness from said central portion to its side edges, and having spacing lugs upon its rear face; and a lifting bar associated with said plate and located centrally there- 0f, and extending substantially parallel with the thickened side edges of the plate.

2. A lining plate for mills, the same being thinnest at its central portion and increasing 1n thickness from said central portion to its' side edges; a.lifting bar associated with said plate and located at the thin central portion thereof, and which bar extends substantially parallel with the thickened side edges of the plate; and securing means located at the central portion only of said plate for securing it in place, the side edges of the plate being left free and unrestrained when the plate is in use.

3. A lining for mills of the class described meteor said plates central portion thereof for holding the same 1n place relative to the inner face of the mill shell, the holding means for each plate being independent of the holding means for the other plates which collectively form the lining.

4. A lining for millsof the class described comprising' a series of separate plates each of which is thinnest at its central portion and the thickness of which plates increases toward their side edges, and which side edges are left free and unrestrained when the mill is in use; a plurality of lifting bars associated one with each of said plates, and which lifting bars are located at the thin central portions of the plates and extend substantially parallel with the thickened side edges thereof; and securing bolts associated with each separate plate and located at the centralportion thereof for holding the same in place relative to the inner face of the mill shell, the thickened side edges of successive plates being spaced apart slightly from one another so that expansion of a plate when the mill is in use will not cause its free side edge to engage the free side edge of the next adjacent plate.

5. A lining for drum mills of the class describedconsisting of a plurality of plates or sections each having a thin central portion With a lifting bar thereon, and thick` cned side edges; the thickened side edges of adjacent sections being parallel with and `spaced apart from each other thereby perof lifting` mills and having an inclined face, and angular openings adapted to receive holding bolts and to prevent their rotation; said bar having bosses surrounding the openings aforesaid and the side Walls of Which bosses merge with the inclined face of the bar. Y

Signed at San Francisco, in the county of San Francisco and State of California. this 25th day of January A. D. 1917.

WALTER S. MCKEE.

Witnesses:

M. V. COLLINS, F. R. TINDELL. 

